Method for producing a ductile tufted product, a ductile tufted product, particularly a ductile tufted top carpet layer, particularly for the automobile interior area

ABSTRACT

The invention is intended to provide a simple and economical method for producing a ductile tufted product, particularly a tufted upper carpet layer that is particularly ductile, in particular for the automotive interior area. For this purpose, a melt-blown non-woven fabric is placed on a ductile polyester tufted backing and the melt-blown non-woven fabric and the polyester tufted backing are tufted together.

TECHNICAL FIELD

The invention relates to a method for producing a ductile tuftedproduct, particularly a ductile tufted top carpet layer produced withit, particularly for the automotive interior area.

For the production of a tufted carpet, a method referred to as tuftingis employed, which is to say a technique for producing three-dimensionalsurfaces, which operates based on the principle of a sewing machine.

During the process, tufting needles introduce a tuft yarn into a basematerial, referred to as the tufted backing. The tufting needles mountedto a needle bar are disposed in the width of the base material, forexample a non-woven fabric, and simultaneously pierce the base material.Before the tufting needles return again upward into their startingposition, the introduced tuft yarn is held on the bottom of the basematerial by hooks, referred to as loopers. In this way loops or pile,referred to as naps, are produced, which in the finished carped form thevisible top (upper layer). Depending on the application, these loops canalready be cut during the tufting process, using special blades. Thisproduces the cut-pile carpets, which are used particularly in theautomotive interior area, preferably at a percentage of over 95%.

DESCRIPTION OF THE INVENTION

It is the object of the invention to provide a method for producing aductile tufted product, particularly an easily ductile tufted top carpetlayer, wherein the method is as simple and economical as possible. Thetop carpet layer produced according to the method is supposed to be usedparticularly in the automotive interior area, or in the properties area.The term “properties area” shall encompass that the top carpet layer isdesigned particularly for high-traffic or extremely strained surfaces,particularly for offices, hotels, airports, hospitals, and the like.

This object is achieved by the characteristics of claim 1.

In the method, a melt-blown non-woven fabric is placed on a ductilepolyester tufted backing, and the melt-blown non-woven fabric and thepolyester tufted backing are tufted together. By applying the melt-blownnon-woven fabric on the tufted backing synchronously with the tuftingprocess, the method is particularly economical.

Due to the special combination of the material selection and the designof the method, the resulting tufted product, particularly as a topautomobile carpet layer for applications in the interior automotivearea, is characterized by particularly good ductility and accordinglyhigh strength, elongation and tear propagation force data.

The dependent claims are advantageous refinements of the subject matterof the invention.

In a preferred embodiment of the method, the tufted product isintroduced in the further carpet manufacturing process solely by athermal treatment from the tufting piercing side, particularly withoutlatex application.

In the tufting production, the latex represents a pretreatment of theraw product for a variety of methods for coating the backing or tuftedbacking. The latex is intended to lock the naps into the base materialand/or the tufted backing. In this way, the desired integration of thenaps is achieved, preventing the pulling of threads or fraying of thepile material. The latex material typically comprises synthetic latexwith filler material.

By eliminating this latex application in the inventive productionprocess, one step is eliminated. In addition, it is more compatible withthe environment because during the production, recycling, and disposalprocesses the waste water is not polluted with latex residue, andbecause during the use of a tufted product treated in this way noemissions are formed by the latex application.

Consequently, the inventive method also satisfies the environmentalstipulations and industrial standards, which have become more stringent,particularly in recent times.

Advantageously, for the method a polyester spun-bond non-woven is usedas the polyester tufted backing, preferably having a basis weight of 70g/m² up to 140 g/m², more preferred from 100 g/m² to 120 g/m².

Furthermore, in the method the melt-blown non-woven fabric having abasis weight of preferably 70 g/m² up to 500 g/m² is used, morepreferred from 80 g/m² to 200 g/m², even more preferred from 80 g/m² to130 g/m².

Due to the particularly low basis weights, the material consumption canbe kept particularly low and the processing speed can be increased,allowing additional cost savings.

According to a preferred embodiment of the method, a thermoplastic rawmaterial that can be spun or processed by injection molding is used asthe raw material for the melt-blown non-woven fabric, particularly oneselected from polyolefins, copolyolefins, polyesters, copolyesters,polyamides, and/or copolyamides having an MFI value (melt flow index)(according to DIN 1238 or ISO 1133) of 100 to 300 g/10 min.

Due to the low viscosity of the melt-blown raw material because of ahigh melt flow index, and the low viscosity of the melt-blown non-wovenfabric that is produced, the penetration of the melted melt-blownnon-woven wear layer in the tufted backing is favored. As a result, athree-dimensional composite layer is produced such that undesirabledelamination between the wear layer and the tufted backing is prevented.

Preferably, a melt-blown non-woven fabric having a thickness of 0.5 mmto 1.5 mm is used, with 0.5 mm to 1.0 mm being particularly preferred.

The fiber titer of the melt-blown non-woven fabric is advantageously0.06 dtex to 0.2 dtex, with 0.06 dtex to 0.1 dtex being preferred.

The bulky, soft melt-blown non-woven wear layer having a high specificfiber surface, lower fiber titer, and high fiber mobility facilitatesthe tufting without needle deviation and increases the number of contactpoints between the melt-blown non-woven wear layer and the fibers of thetufted backing, thus evenly strengthening the bond between the wearlayer and the tufted backing across the cross-section.

The joint tufting of the melt-blown non-woven fabric and polyestertufted backing preferably occurs without prior needling or calendaringwith a gauge of ⅛″ to 1/16″.

Alternatively, the melt-blown non-woven fabric is advantageouslystrengthened by an ultrasonic calendar having a bonding surface of lessthan 5%, preferably of less than 2%, and tufted together with thepolyester tufted backing with a gauge of ⅛″ to 1/16″.

In a particularly preferred embodiment of the method, the melt-blownnon-woven fabric and the polyester tufted backing are strengthenedtogether by an ultrasonic calendar having a bonding surface of less than5%, preferably of less than 2%, and tufted together with the polyestertufted backing with a gauge of ⅛″ to 1/16″.

Due to the joint strengthened, particularly good handling and betterprocess stability than in the case of separate layers are guaranteed.Furthermore, the combination with the very small bonding surface at thesame time allows sufficiently high fiber mobility, so that fiber damageduring tufting can at least be reduced, thus increasing the quality ofthe tufted product, particularly with respect to ductility.

In a further carpet production process, preferably an acoustic non-wovenmaterial and/or at least one other insulating layer, for example a heavylayer having basis weights of, for example, 2 to 7 kg/m² made ofethylene-vinyl acetate/ethylene-propylene-diene rubber, or coextrudedfilm comprising polyethylene/polyamide (polyethylene), is applied to thetufting piercing side of the tufted product.

The tufted products produced according to the invention, at a tearpropagation force in the longitudinal direction at room temperature(according to DIN 53859-3) of preferably 170 N to 240 N, have aparticularly high tear propagation force value, and thereforeparticularly good ductility, so that these tufted products areparticularly well suited for use as top carpet layers in the automotiveinterior area as automobile top carpet layers.

The ductile tufted products, particularly the ductile tufted automobiletop carpet layers, at room temperature furthermore preferably have

a maximum tensile force in the longitudinal direction (according to EN29073-3) of 250 N/5 cm to 400 N/5 cm, more preferred of 275 N/5 cm to375 N/5 cm,

a maximum tensile force in the transverse direction (according to EN29073-3) of 180 N/5 cm to 300 N/5 cm, more preferred of 203 N/5 cm to250 N/5 cm,

a maximum tensile elongation in the longitudinal direction (according toEN 29073-3) of 45% to 60%, and

a maximum tensile elongation in the transverse direction (according toEN 29073-3) of 42% to 55%.

At 140° C., the ductile tufted products, particularly the ductile tuftedautomobile top carpet layers, advantageously have

a maximum tensile force in the longitudinal direction (according to EN29073-3) of 185 N/5 cm to 200 N/5 cm,

a maximum tensile force in the transverse direction (according to EN29073-3) of 85 N/5 cm to 120 N/5 cm,

a maximum tensile elongation in the longitudinal direction (according toEN 29073-3) of 65% to 70%, and

a maximum tensile elongation in the transverse direction (according toEN 29073-3) of 65% to 70%.

EXECUTION OF THE INVENTION

The subject matter of the invention will be explained in more detailbased on an example.

Production of a Melt-Blown Non-Woven Fabric:

As the raw material for the melt-blown non-woven fabric, polyethylenehaving a melt flow index (MFI) of 155 g/10 min according to DIN 1133 isused and spun through a melt-blowing spinneret. The polyethylene fibersobtained in this way have a fiber titer of 0.07 dtex.

Thereafter, the fibers are deposited in a suction drum, which has adistance of approximately 600 mm to the spinning nozzle, in order toproduce a bulky and soft fibrous web, the fiber mobility of which ismaintained in the tufting process.

The fibrous web weighing 80 g produced in this way can then optionallybe strengthened by means of an ultrasonic calendar using light sonotrodepressing pressures of about 0.006 bar with a bonding surface of lessthan 5%, preferably of less than 2%, thus obtaining a stillsubstantially bulky non-woven fabric. Alternatively, also light thermalstrengthening using engraved or roughened calendaring rollers isconceivable.

Production of a Tufted Product:

The melt-blown non-woven fabric weighing 80 g produced according to theabove-described method in the present case is placed on the tuftedbacking in non-strengthened form and strengthened only together with thetufted backing by means of an ultrasonic calendar using light sonotrodepressing pressures of about 0.006 bar with a bonding surface of about1.6%. A polyester spun-bond non-woven material, Lutradur® LDT 5312(Freudenberg), having a basis weight of 120 g/m² is used as the tuftedbacking.

This composite made of melt-blown non-woven fabric and polyester tuftedbacking, the composite being slightly prestrengthened by means ofultrasound, is fed to the tufting loom infeed, wherein the melt-blownnon-woven fabric side represents the needle or tufting piercing side.

The laboratory tufting loom has a needle working width of about 50 cmand a needle gauge of 1/10 inch (10 needles per 2.54 cm) pile quality.

The stitch density is about 56/10 cm. A BCF yarn, which is a bulkedcontinuous filament, is used as the tuft yarn and has a polyamide 6quality having a total strength of 1300 dtex and 128 individualfilaments. Other conventional tuft yarns can likewise be used.

The tuft yarn weight is about 400 g/m². The complete laboratory tuftingarrangement produces, in the narrow width, a carpet design that istypically used in the automotive field (with the exception of theadditionally inserted layer).

Before the tufting needles return again, the inserted tuft yarn is heldby hooks such that loops or naps are produced. In this way, a loop pilecarpet is produced. If the loops, as in this example, are cut with ablade, a cut-pile carpet is produced.

After the melt-blown non-woven fabric has been tufted together with thepolyester tufted backing, thermal treatment is provided from the tuftingpiercing side until the polyethylene of the melt-blown non-woven fabrichas melted. The top carpet layer produced in this way is analyzed forthe following properties.

Properties of the Top Carpet Layer Produced in this way at RoomTemperature:

maximum tensile force in the longitudinal direction (according to EN29073-3): 368 N/5 cm

maximum tensile force in the transverse direction (according to EN29073-3): 203 N/5 cm

maximum tensile elongation in the longitudinal direction (according toEN 29073-3): 58%

maximum tensile elongation in the transverse direction (according to EN29073-3): 44%

tear propagation force in the longitudinal direction (according to DIN53859-3): 218 N

The higher the values of the tear propagation force, the higher theductility.

By comparison, the tear propagation force of the tufted backing alone(Lutradur® LDT 53 12, 120 g/m²), which is to say without the melt-blownnon-woven fabric, is 198 N, and the tear propagation force of the tuftedbacking (Lutradur® LDT 5312, 120 g/m²) having a conventional latex orlatex binder treatment (approx. 100 g/m²) is 150 N.

With a conventional latex treatment, ductility is consequentlynegatively influenced, while the tufted product manufactured accordingto the invention has a particularly high tear propagation force valueand therefore particularly good ductility, so that this tufted productis particularly well-suited for use as a top carpet layer in theautomotive interior area.

Properties of the Top Carpet Layer Produced in this way at 140° C.:

maximum tensile force in the longitudinal direction (according to EN29073-3): 196 N/5 cm

maximum tensile force in the transverse direction (according to EN29073-3): 111 N/5 cm

maximum tensile elongation in the longitudinal direction (according toEN 29073-3): 75%

maximum tensile elongation in the transverse direction (according to EN29073-3): 69%

In addition to determining the force and elongation behaviors of thetufted product by means of measurements on a tensile elongation testmachine, the ductility properties of the tufted product were determinedusing an internal measuring method. To this end, circular samples of thetufted product having a diameter of 24 cm are punched out, clamped in aclamping ring, and fixed by means of brass screws and threaded bolts. Atthe back, which is to say from the tufting piercing side, the fixedsample is heated by infrared heating to a defined temperature, in thepresent example to 140° C., wherein a constant distance of 16 cm to theinfrared field is maintained.

After reaching the temperature, the clamping ring with the carpet samplefixed thereon is automatically placed on a displaceable hollow cylinder,which travels upward at a speed of 50 mm/s against a metal ball. Themetal ball is cooled with water to 18° C. and has a diameter of 10 cm.In this process, the carpet sample is deformed from the tufting piercingside. The deformation depths that are measured are used to compute thedeformation in percent.

At a maximum deformation depth of 12.2 cm, maximum deformation is: 106%and the maximum deformation force is: 1543 N. At a deformation depth of9 cm, maximum deformation is:  50% and the maximum deformation force is: 723 N.

The example of the top carpet layer produced according to the inventionhas the further advantage that it can be laminated with a heavy layer,without the additional application of polyethylene powder, which iscommon in the conventional carpet industry. Dispensing with thispolyethylene powder application can be attributed to the fact that abonding agent layer made of polyethylene is already provided on thecarpet piercing side of the top carpet layer in the example.

1. A method for producing a ductile tufted product, particularly aductile tufted top carpet layer, particularly for the automotiveinterior area, wherein a melt-blown non-woven fabric is placed on aductile polyester tufted backing, and wherein the melt-blown non-wovenfabric and the polyester tufted backing are tufted together.
 2. Themethod according to claim 1, wherein the tufted product is introduced inthe further carpet manufacturing process solely by a thermal treatmentfrom the tufting piercing side, particularly without latex application.3. The method according to claim 1, wherein a polyester spun-bondnon-woven is used as the polyester tufted backing, preferably having abasis weight of 70 g/m² up to 140 g/m², more preferred from 100 g/m² to120 g/m².
 4. A method according to claim 1, wherein the melt-blownnon-woven fabric having a basis weight of preferably 70 g/m² up to 500g/m² is used, more preferred from 80 g/m² to 200 g/m², even morepreferred from 80 g/m² to 130 g/m².
 5. A method according to claim 1,wherein a thermoplastic raw material that can be spun or processed byinjection molding is used as the raw material for the melt-blownnon-woven fabric, particularly one selected from polyolefins,copolyolefins, polyesters, copolyesters, polyamides, and/or copolyamideshaving an MFI value (melt flow index) (according to DIN 1238 or ISO1133) of 100 to 300 g/10 min.
 6. A method according to claim 1, whereinthe melt-blown non-woven fabric having a thickness of 0.5 mm to 1.5 mmis used, with 0.5 mm to 1.0 mm being particularly preferred.
 7. A methodaccording to claim 1, wherein the melt-blown non-woven fabric having afiber titer of 0.06 dtex to 0.2 dtex, preferably of 0.06 dtex to 0.1dtex, is used.
 8. A method according to claim 1, wherein the melt-blownnon-woven fabric and the polyester tufted backing are tufted togetherwith a tufting gauge of ⅛″ to 1/16″ without prior needling orcalendaring.
 9. A method according to claim 1, wherein the melt-blownnon-woven fabric is advantageously strengthened by means of anultrasonic calendar with a bonding surface of less than 5%, preferablyof less than 2%, and tufted together with the polyester tufted backingwith a gauge of ⅛″ to 1/16″.
 10. A method according to claim 1, whereinthe melt-blown non-woven fabric and the polyester tufted backing arestrengthened together by means of an ultrasonic calendar with a bondingsurface of less than 5%, preferably of less than 2%, and tufted togetherwith a gauge of ⅛″ to 1/16″.
 11. A method according to claim 2, whereinan acoustic non-woven material and/or at least one other insulatinglayer is applied on the tufting piercing side of the tufted product as afurther carpet manufacturing process.
 12. A ductile tufted product,particularly a ductile tufted top carpet layer, particularly for theautomotive interior area, produced using a method according to claim 1,which at room temperature has: a maximum tensile force in thelongitudinal direction (according to EN 29073-3) of 250 N/5 cm to 400N/5 cm, preferably of 275 N/5 cm to 375 N/5 cm); a maximum tensile forcein the transverse direction (according to EN 29073-3) of 180 N/5 cm to300 N/5 cm, preferably of 203 N/5 cm to 250 N/5 cm; a maximum tensileelongation in the longitudinal direction (according to EN 29073-3) of45% to 60%; and a maximum tensile elongation in the transverse direction(according to EN 29073-3) of 42% to 55%.
 13. A ductile tufted product,particularly a ductile tufted top carpet layer, particularly for theautomotive interior area, produced using a method according to claim 1,which at 140° C. has: a maximum tensile force in the longitudinaldirection (according to EN 29073-3) of 185 N/5 cm to 200 N/5 cm; amaximum tensile force in the transverse direction (according to EN29073-3) of 85 N/5 cm to 120 N/5 cm; a maximum tensile elongation in thelongitudinal direction (according to EN 29073-3) of 65% to 70%; and amaximum tensile elongation in the transverse direction (according to EN29073-3) of 65% to 70%.
 14. A ductile tufted product, particularly aductile tufted top carpet layer, particularly for the automotiveinterior area, produced using a method according to claim 1, which atroom temperature has a tear propagation force in the longitudinaldirection (according to DIN 53859-3) of 170 N to 240 W.